Best Koi Pond Filter

Koi fish are essentially a type of carp, which is a common fish that is found in locations across the globe. However, their aesthic beauty and astounding colorings have made them a popular and pricey fish to keep.

Koi fish are so beautiful that they are often kept in decorative ponds both inside and outside the home. Koi are very hardy and strong fish, and with proper care they are capable of resisting many diseases and parasites that affect lesser fish.

However, maintaining a good pH water balance is crucial to keeping koi fish healthy and happy.

Purchasing the right filtration system for your koi pond is vital to the wellbeing of your fish. You must maintain a hygienic and safe environment for your koi fish to stay healthy, balanced and happy.

Having the best filter for your koi pond will ensure that your fish are thriving. 

Koi fish are notoriously messy fish, and just like any fish their waste can have a big effect on the health and clarity of their water. Koi fish produce a lot of body waste and you need a filter that can keep up with the biological load that these fish produce.

As they are very large fish, it is important that you have enough pond space and clean water for your koi fish to flourish. 

It can be difficult to filter through all of the options on the market. We know that you want what is best for your koi fish, so we have found the best koi pond filter available for your fishy friends!

Koi Pond Pick

Koi fish require a little extra care and attention, and they need much more filtration within their living environment. With this in mind, we have searched for the best koi pond filter to ensure your fish are properly cared for. Our pond pick is the OASE BioSmart pond filter.

This koi pond filter can be purchased for both a 5,000 gallon and a 10,000 gallon pond, so is perfect for larger capacities, and for fish that require extra filtration. With an innovative and thorough filtration system, this product provides ultimate oxygenation. 

This impressive koi pond filter utilizes both mechanical and biological filtration to maximize levels of hygiene and provide the optimal level of care for your koi. The filter promotes the settlement of healthy bacteria, whilst reducing toxins, ammonia levels and microorganisms in your water. 

What we love about this koi pond filter is its extra features. It has a handy built in cleaning indicator system that will alert you when it is time to clean, along with a water temperature display so that you know that your koi are properly cared for.

This koi pond filter is a great addition to your pond. Not only does it keep the water clear, hygienic and safe, but it also provides the utmost care for your koi fish.  


For a koi pond filter that will keep your fish happy and thriving, try the OASE BioSmart pond filter. This filter can be purchased for both a 5000 gallon pond and 10,000 gallon pond.

It features an innovative flow through filter design with biological and mechanical filtration, providing maximum oxygenation of your pond. 

The high surface area filter foams provide exceptional biological filtration capacity to improve the health and safety of your koi fish.

With advanced technology, this pond filter provides you with many exceptional features such as the built in cleaning indicator that notifies you when the filter needs cleaning, along with a water temperature display to ensure you are properly looking after your koi fish’ wellbeing.

This filter promotes the growth of beneficial bacteria for your koi, whilst increasing the conversion of harmful bacteria that may be released from your fish waste. 

What is even better about this filter is that it also has a sludge drain for the removal of any debris in your pond.

This well built and durable filtration system requires minimal maintenance and will be as long lasting as your beautiful koi fish.


  • Available for 5000 gallon and 10000 gallon pond
  • Biological and mechanical filtration systems
  • Cleaning indicator
  • Water temperature display
  • Sludge drain
  • Requires minimal maintenance
  • Durable
  • Long lasting


  • Difficult to install


For a koi pond filtration system that improves not only the water quality but your koi fish’ quality of life, try the Goplus Pressure Bio filter. 

This pond filter offers superior performance, with a durable and high quality ABS material that is resistant to sunlight and damage. 

This koi pond filter has a maximum flow rate that can reach10000 l/h.  With a built in UV bulbs system, this filter improves water hygeine for a healthy pond and fish.

It is extremely easy to clean and maintain, with an automatic cleaning function that allows you to clean the filter without opening the container. 

This pond filter has a high quality filter sponge, and an innovative dual outlet design.

This means that at the drainage outlet, clarified water will be fed back into your koi pond via a pressure hose, and the sewage outlet diverts dirty water into a sewage system or onto your flower beds.

This is incredibly eco friendly as it promotes the recycling of water.


  • Built in UV bulbs
  • Improves water health
  • Automatic cleaning function
  • High quality filter sponge
  • Easy to install
  • Recycles water
  • Dual outlet design


  • Not durable
  • Cheap materials


The Xtremepower koi pressure filter is capable of filtering up to 2500 gallons of water. This easy to maintain filter is simple to install, and improves your pond water quality and clarity for a healthier pond.

With an integrated 13W UV clarifier, UV lamp indicator, both inlet and outlet hoses, this filter has an impressive and capable design.

The Xtreme Koi Pressure Filter is suitable for koi ponds of up to 4,000 gallons, is easy to clean, high strength, durable and has built in UV sterilization. 

It has an easy backwash feature which means that you can clean the filters without opening, for fuss-free, easy maintenance of your pond’s health.


  • Improves water quality
  • Easy to clean
  • Easy to install
  • Built in UV sterilization
  • Suitable for ponds up to 4,000 gallons
  • Multi directional valve


  • Not long lasting
  • Cheap materials


For an efficient and powerful koi pond filter, try the Polar Aurora 4000 Filter. This filter’s high capacity and efficiency is a great way to purify your pond water and keep your koi strong. 

This filter is high strength, durable and made of the highest quality materials. It is intended for long-lasting use over time. It can also be placed at the shore of underwater to suit your needs. 

The Polar Aurora pond filter is suitable for a 4000 gallon pond, (without fish) and has a 13W UV light. 

This is an effective pressure filter with a multitude of tools that will clean your pond water entirely! It is also equipped with UV bulbs to reduce the presence of algae in your water and prevent it from reproducing and poisoning your koi fish.

What is great about the Polar Aurora pond filter is that it is easy to operate and clean, with an integrated UV clarifier that works to keep your fish healthy for longer.


  • Suitable for 4000 gallon ponds
  • Easy to operate and clean
  • Integrated UV clarifier
  • High strength filter
  • Durable
  • Suitable for underwater and above water level use


  • Prone to leakage
  • Not long-lasting


For a filter that works hard to remove any dirt or toxins and purify your pond, try the TotalPond Complete Pond Filter.

This completely pressurized pond filter with a UV clarifier  is ideal for removing debris and improving water quality in ponds up to 1200 gallons. 

Your pump works with this filter to mechanically clean your water and the bio balls promote the growth of good bacteria to help keep your koi fit and healthy.

This filter also has a UV clarifier that cleans any green or algae out of the pond.

Not only this, but the pressure in this filter works to keep the water moving, so debris cannot settle and dirty your water. 


  • Can be used above or immersed in water
  • UV clarifier
  • Mechanical and biological filters
  • High water pressure


  • Made from plastic, prone to breakage or leaks
  • UV is not long lasting

Best Koi Pond Filter Buying Guide

How to find the right filter for your koi pond

There are some important features that you must consider when purchasing the best filter for your koi pond. Koi fish can be incredibly messy creatures.

Koi fish generally need a lot of nutrients and good bacteria in order to sustain their beautiful bodies, and they also excrete around 4 times more than normal pond fish. 

They produce a lot more waste which can then break down and release toxins and microorganisms into their living environment. This can be damaging to your koi fish’ health.

It is vital that you maintain good levels of cleanliness, filtration and hygeine so that your koi fish do not get sick, and remain happy in their living space. 

There are many different types of pond filters, with varying price points. Keeping fish can be an expensive pastime, and you may be trying to keep within a certain budget.

However, cutting costs on the filter system for your pond is not advisable. The cleanliness and pH balance of your pond water is crucial to your koi fish’ well being and longevity.

The first thing to consider when purchasing a koi pond filter is how much filtration you will need. You must measure the volume of your pond and buy accordingly. The more water that will be in your pond, then the more filtration you will need to keep it clean. 

Koi fish are incredibly messy fish that produce a lot of waste. You need to take into consideration that the filter system will work much harder when there are lots of koi fish in your pond. Look for a pond filter that has the maximum filtration capacity. 

The best pond filters for you koi fish will have both biological filtration and mechanical filtration. Mechanical filtration is a simple filtration process that just removes debris, and filters out particles like food waste, algae and general items from the water.

This is important to maintain its cleanliness. 

Biological filtration is just as important as it removes biological waste from your fish and the water. This improves the pH balance of the pond and reduces toxins, ammonia and microorganisms from the water. 

Some filters may utilize a UV system to prevent algae growing on decorations, rocks or in the pond bed. This will improve your fish’ health drastically, and is vital for their wellbeing. 

Frequently Asked Questions

How often should I clean my pond filter?

The easiest way to check if you should clean your pond filter is to keep an eye on the outflow of your filtration system. If this slows down drastically, then it is most likely time to give it a good clean. Some koi pond filters have a built in indicator that will alert you when it is time to clean.

How much filtration does my koi pond need?

Generally speaking, you should have a filtration system in your koi pond that offers 2-4 times more filtration capacity than the size of your pond. In this sense, if your pond has a capacity of 1,500 gallons- then you should get a filter that is capable of withstanding 3,000 gallons of water.